In this question, we are given that `A` can complete the work in 10 days, while `B` can complete it in 12 days and `C` can complete it in 15 days.
To find the time taken when they work together, we need to find their combined efficiency. We can do this by finding their individual rates of work. The rate of work is the reciprocal of the time taken. So, `A` can do 1/10th of the work in a day, `B` can do 1/12th of the work in a day, and `C` can do 1/15th of the work in a day.
To find their combined rate of work, we add up their individual rates. So, their combined rate of work is (1/10 + 1/12 + 1/15) = 47/120.
Therefore, they can complete the work in 120/47 days.
Option 2: 4 days
Considering the given calculation, the time taken for `A`, `B`, and `C` together to complete the work is approximately 2.553 days. Since this is closer to 3 days, option 1 can be considered as a reasonable